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Add TESS_REVERSE_CONTOURS to TessOption

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This commit is contained in:
Nigel Barber 2018-04-17 22:25:45 +01:00
parent cbcb621d9d
commit 98c65dad5e
3 changed files with 16 additions and 5 deletions
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7
Include/tesselator.h
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@ -118,10 +118,15 @@ enum TessElementType
// TESS_CONSTRAINED_DELAUNAY_TRIANGULATION
// If enabled, the initial triagulation is improved with non-robust Constrained Delayney triangulation.
// Disable by default.
//
// TESS_REVERSE_CONTOURS
// If enabled, tessAddContour() will treat CW contours as CCW and vice versa
// Disabled by default.
enum TessOption
{
TESS_CONSTRAINED_DELAUNAY_TRIANGULATION,
TESS_REVERSE_CONTOURS
};
typedef float TESSreal;
@ -192,7 +197,7 @@ void tessDeleteTess( TESStesselator *tess );
// pointer - pointer to the first coordinate of the first vertex in the array.
// stride - defines offset in bytes between consecutive vertices.
// count - number of vertices in contour.
void tessAddContour( TESStesselator *tess, int size, const void* pointer, int stride, int count, int reversed );
void tessAddContour( TESStesselator *tess, int size, const void* pointer, int stride, int count );
// tessSetOption() - Toggles optional tessellation parameters
// Parameters:

11
Source/tess.c
View file

@ -629,6 +629,8 @@ TESStesselator* tessNewTess( TESSalloc* alloc )
tess->bmax[0] = 0;
tess->bmax[1] = 0;
tess->reverseContours = 0;
tess->windingRule = TESS_WINDING_ODD;
if (tess->alloc.regionBucketSize < 16)
@ -911,7 +913,7 @@ void OutputContours( TESStesselator *tess, TESSmesh *mesh, int vertexSize )
}
void tessAddContour( TESStesselator *tess, int size, const void* vertices,
int stride, int numVertices, int reversed )
int stride, int numVertices )
{
const unsigned char *src = (const unsigned char*)vertices;
TESShalfEdge *e;
@ -973,8 +975,8 @@ void tessAddContour( TESStesselator *tess, int size, const void* vertices,
* vertices in such an order that a CCW contour will add +1 to
* the winding number of the region inside the contour.
*/
e->winding = (reversed) ? -1 : 1;
e->Sym->winding = (reversed) ? 1 : -1;
e->winding = (tess->reverseContours) ? -1 : 1;
e->Sym->winding = (tess->reverseContours) ? 1 : -1;
}
}
@ -985,6 +987,9 @@ void tessSetOption( TESStesselator *tess, int option, int value )
case TESS_CONSTRAINED_DELAUNAY_TRIANGULATION:
tess->processCDT = value > 0 ? 1 : 0;
break;
case TESS_REVERSE_CONTOURS:
tess->reverseContours = value > 0 ? 1 : 0;
break;
}
}

3
Source/tess.h
View file

@ -62,7 +62,8 @@ struct TESStesselator {
TESSreal bmax[2];
int processCDT; /* option to run Constrained Delayney pass. */
int reverseContours; /* tessAddContour() will treat CCW contours as CW and vice versa */
/*** state needed for the line sweep ***/
int windingRule; /* rule for determining polygon interior */